regulator: Allow parsing custom properties when using simplified DT parsing

When drivers use simplified DT parsing method (they provide
'regulator_desc.of_match') they still may want to parse custom
properties for some of the regulators. For example some of the
regulators support GPIO enable control.

Add a driver-supplied callback for such case. This way the regulator
core parses common bindings offloading a lot of code from drivers and
still custom properties may be used.

The callback, called for each parsed regulator, may modify the
'regulator_config' initially passed to regulator_register().

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

4 files changed, 27 insertions, 1 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index c13b557a560e..5fae8cabd254 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3635,7 +3635,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
                 return ERR_PTR(-ENOMEM);
         }
 
-        init_data = regulator_of_get_init_data(dev, regulator_desc,
+        init_data = regulator_of_get_init_data(dev, regulator_desc, config,
                                                &rdev->dev.of_node);
         if (!init_data) {
                 init_data = config->init_data;
diff --git a/drivers/regulator/internal.h b/drivers/regulator/internal.h
index 80ba2a35a04b..c74ac8734023 100644
--- a/drivers/regulator/internal.h
+++ b/drivers/regulator/internal.h
@@ -38,11 +38,13 @@ struct regulator {
 #ifdef CONFIG_OF
 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
                                  const struct regulator_desc *desc,
+                                 struct regulator_config *config,
                                  struct device_node **node);
 #else
 static inline struct regulator_init_data *
 regulator_of_get_init_data(struct device *dev,
                            const struct regulator_desc *desc,
+                           struct regulator_config *config,
                            struct device_node **node)
 {
         return NULL;
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 91eaaf010524..24e812c48d93 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -270,6 +270,7 @@ EXPORT_SYMBOL_GPL(of_regulator_match);
 
 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
                                             const struct regulator_desc *desc,
+                                            struct regulator_config *config,
                                             struct device_node **node)
 {
         struct device_node *search, *child;
@@ -307,6 +308,16 @@ struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
                         break;
                 }
 
+                if (desc->of_parse_cb) {
+                        if (desc->of_parse_cb(child, desc, config)) {
+                                dev_err(dev,
+                                        "driver callback failed to parse DT for regulator %s\n",
+                                        child->name);
+                                init_data = NULL;
+                                break;
+                        }
+                }
+
                 of_node_get(child);
                 *node = child;
                 break;
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 5f1e9ca47417..d4ad5b5a02bb 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -21,6 +21,7 @@
 
 struct regmap;
 struct regulator_dev;
+struct regulator_config;
 struct regulator_init_data;
 struct regulator_enable_gpio;
 
@@ -205,6 +206,15 @@ enum regulator_type {
  * @supply_name: Identifying the regulator supply
  * @of_match: Name used to identify regulator in DT.
  * @regulators_node: Name of node containing regulator definitions in DT.
+ * @of_parse_cb: Optional callback called only if of_match is present.
+ *               Will be called for each regulator parsed from DT, during
+ *               init_data parsing.
+ *               The regulator_config passed as argument to the callback will
+ *               be a copy of config passed to regulator_register, valid only
+ *               for this particular call. Callback may freely change the
+ *               config but it cannot store it for later usage.
+ *               Callback should return 0 on success or negative ERRNO
+ *               indicating failure.
  * @id: Numerical identifier for the regulator.
  * @ops: Regulator operations table.
  * @irq: Interrupt number for the regulator.
@@ -251,6 +261,9 @@ struct regulator_desc {
         const char *supply_name;
         const char *of_match;
         const char *regulators_node;
+        int (*of_parse_cb)(struct device_node *,
+                            const struct regulator_desc *,
+                            struct regulator_config *);
         int id;
         bool continuous_voltage_range;
         unsigned n_voltages;